1. Field of the Invention
The present invention relates to a method of reducing local noise in holographic images stored in volume holographic memories.
2. Related Art
Recent extensive results at various places have shown that holographic memory has a great potential for a future memory with large storage capacity of one trillion bits per cubic centimeters and fast random access of approximately one million pages per second.
However, an image reconstructed from a holographic memory is significantly degraded by various interference fringes originating from dust on optical components, unwanted reflection from various surfaces, etc. As a result, signal-to-noise ratio (SNR) and storage capacity of a holographic memory is greatly reduced, posing a serious bottleneck in the practical use of holographic memory.
Although, there have been approaches suggested to reduce the coherent noise, most of them are either impractically complicated, poor in performance, or time-consuming. Furthermore, most of this previous work did not consider noise from SLMs (Spatial Light Modulators) or CCDs (Charge Couple Devices).